panic wrote:Limiting the selection to 1948-55, are there any important structural differences between the 1948, 1950 and 1955 heads (headbolt insert depth, wall thickness, etc.)?Is any intake or exhaust port known to flow better?

Panic,I can't say why exactly, but I always had the best results performance wise with the '55 motor. I suspected that the combination of the timken sprocket side and the lower friction on the pinion side as compared to later motors allowed the '55 to be beat harder than the early pans before it broke. I never really thought about how the heads flowed. My partner who lived and died with pans always preferred the outside oiler heads for performance use. He used manley valves and guides with a 5 angle valve job, no porting and a modern carb. I was a neandertal and just put on shovel stuff. It was my favorite bottom end for 4 1/2" S&S wheels and a shovel top with Jerry's heads and mikuni set up.

The '55 heads, being the first year of the o-ring manifold (instead of the plumber) would make more sense from a flow standpoint, since you don't have to deal with a transition from the screw in nipple to the port itself. It is tough to get a really nice transition without cutting into a lot of threads. If, on the other hand you planned to install the weld in o-ring adapters I don't believe there would be much difference. In my experience, the flow difference/ and flow potential from head to head is in the core shift which does not seem to be related to the year. However, I have ported less than a dozen sets of Panheads over the years, so I certainly could have missed some trends in the ports castings for different years.

Let me correct that: the first rude person who never wishes any help from me again.As my last 1,000 or so posts will show, information flow basically works in one direction: I answer questions, but get few answers. I'm not really inconvenienced by simply ignoring this board.Quote this one, and see what happens.

panic wrote:Let me correct that: the first rude person who never wishes any help from me again.As my last 1,000 or so posts will show, information flow basically works in one direction: I answer questions, but get few answers. I'm not really inconvenienced by simply ignoring this board.Quote this one, and see what happens.

Panic, I am so happy to see that you are finally developing a sense of humor. Isn't it way less stressful now that you have decided not to take yourself (and others) so seriously? Philippians 2:3 can be our new motto.

Panic....you should go over all the posts, all 81,637 of them. The majority of posts made are from folks who offer help and suggestions to the inquiring minds who asked the questions. There are far less posts made asking questions than there are posts offering answers and suggestions to those questions. Pa

I was referring specifically, for example, to this post. Since my comment begins with "Limiting the selection to 1948-55", I was annoyed (but not surprised) to see that rather than offer assistance, someone was happy instead to show how much smarter they are than I am - by ignoring the question, and instead explaining something I already know.Need more?I asked if Linkert correction air volume was controlled by the hole size. The responses I got were, shall we say, disappointing, in that it was "explained" to me that the size meant nothing (which, of course, is why there are 5 or 6 different sizes - because they don't do anything) and that correction air isn't controlled at all.Since this is completely false, but spoken with absolute assurance by an "expert", I decided not to waste his time and mine by asking him anything else.I also foolishly remarked that weighing rods end for end depended on their center of gravity - to which again I was told "no, it doesn't", with the same confidence that once explained how the world is flat. Again: rather than attempt to "prove" something that needs no proof, I gave up.I'm also amused to ask a fairly technical question, and receive the full attention of someone whose grasp of the subject is so poor that he doesn't even understand what my question is (let alone provide an answer), and instead supplies cut-n-paste boilerplate "Mr. Science explains how an engine works" (high school level) such as "mixture must be optimized" and "cam timing depends on engine design". This would have been helpful for me before 1960, otherwise not.

These are not matters subject to opinion, or belief, or even testing. It doesn't matter who agrees, or doesn't, or how popular, or how many times it's repeated.

panic wrote:I was referring specifically, for example, to this post. Since my comment begins with "Limiting the selection to 1948-55", I was annoyed (but not surprised) to see that rather than offer assistance, someone was happy instead to show how much smarter they are than I am - by ignoring the question, and instead explaining something I already know.Need more?I asked if Linkert correction air volume was controlled by the hole size. The responses I got were, shall we say, disappointing, in that it was "explained" to me that the size meant nothing (which, of course, is why there are 5 or 6 different sizes - because they don't do anything) and that correction air isn't controlled at all.Since this is completely false, but spoken with absolute assurance by an "expert", I decided not to waste his time and mine by asking him anything else.I also foolishly remarked that weighing rods end for end depended on their center of gravity - to which again I was told "no, it doesn't", with the same confidence that once explained how the world is flat. Again: rather than attempt to "prove" something that needs no proof, I gave up.I'm also amused to ask a fairly technical question, and receive the full attention of someone whose grasp of the subject is so poor that he doesn't even understand what my question is (let alone provide an answer), and instead supplies cut-n-paste boilerplate "Mr. Science explains how an engine works" (high school level) such as "mixture must be optimized" and "cam timing depends on engine design". This would have been helpful for me before 1960, otherwise not.

These are not matters subject to opinion, or belief, or even testing. It doesn't matter who agrees, or doesn't, or how popular, or how many times it's repeated.

"I'm also amused to ask a fairly technical question, and receive the full attention of someone whose grasp of the subject is so poor that he doesn't even understand what my question is"...

Panic please don't take offence....

The above partial quote is part of the reason that for me, I am here......to bring my level of understandings UP, to the level of others such as yourself (but that ain't gonna happen).... if it is not for reading the posts thats posted here and at other sites that I vistit...how is one to learn?

Ain't super smart...don't have stacks and stacks of books and magazines.......aint rich... just making a living, and finally learning about something the does interest me. And visiting these sites at times prevents me from making mistakes that cost's one in time and money.

I welcome questions that show that the interested party has already made some attempt to resolve the issue, but would like either guidance (tell me where not to waste time), a better source, or just an answer.What I dislike is to make a factual response, and have it disputed, as if "every question has 2 sides".After a few decades (my first computer: 1983), I've found that the Internet is beyond doubt the best thing that ever happened to to the self-proclaimed expert ("why shouldn't my answer be as good as anyone else's?") since there is no IQ test, no credentials, and the audience is (pardon me for saying this) does not always detect things that sound impressive, or have been widely repeated, but are in fact nonsense.The inability to determine whether a question may be resolved by fact, history, physics, laws of nature etc. as opposed to opinion appears to be a skill as little prized today as it was when the Church made Galileo recant."I favor an S&S over a Keihin" is an opinion, and nothing more, even if your reasons are overwhelming."Ford invented the flathead engine" (my dispute of this statement got me banned from a Buick BBS) was made as a statement of fact by a "patent holder" and "consultant to Honda" with "many years as a race car designer" (he's still around, name on request), but is completely wrong - and no one on that board knew it, so they agreed that I had insulted their friend.

In future, please note that when a disagreement occurs here, I am not, ever, the first one to make an attack on the other person, merely on his statement.

Chris Haynes wrote:My question is why would you use the Plumber style heads when better designs are available?

Chris!

WIth the modern replacement of PEEK material for brass seals, the plumber's design is now far superior to the temporary O-ring design.

...Cotten

I agree with you Cotten. But if I was building a go fast Panhead I would use the STD castings that used the Y shaped manifold rather than the T shape. Harley learned the the Y was far superior to the T during VL production. The early VL's had the T manifold and the new improved TNT motor had the Y shape. Why they went back to the T with the Knucks is a mystery to me.